In this proposal we plan to elicit offensive threat and attack in cats by electrical stimulation of the brain, to investigate how cats approach and select objects of attack, to continue anatomical studies of the neural pathways involve in attack, to investigate the interrelations between various attack sites in the brain, and to record the activities of single units in the brain that are relevant to attack. Comparisons between the cat and stumptailed monkey in terms of the brain mechanisms involved in attack will also be made. In the cat the functional capabilities of a segment of the brain below the midbrain will be studied.